Fluxmail and EmailEngine both connect existing mailboxes through self-hosted MCP and REST APIs. Fluxmail includes local stdio, a CLI, and a free Personal plan. EmailEngine adds inbound webhooks, queues, and mail merge; its native MCP endpoint is in beta.
Reviewed
Choose Fluxmail for local stdio clients, a CLI that shares the email API, or a small deployment with SQLite and an ongoing free plan. Choose EmailEngine when inbound webhooks, queues, templates, or mail merge are central to your application. Both support MCP clients and scoped mailbox access.
| Feature | Fluxmail | EmailEngine |
|---|---|---|
| Architecture | ||
| Deployment | Local process or Docker | Self-hosted server Local, cloud, on-premises, or Docker |
| Primary interface | MCP, REST API, and CLI | REST API, webhooks, and MCP (beta) |
| Native MCP server | Yes stdio and Streamable HTTP | Yes, in beta Native /mcp endpoint; disabled until enabled by an administrator |
| Storage dependency | SQLite Stored on the Fluxmail machine | Redis EmailEngine requires a Redis instance |
| Real-time webhooks | Not a core interface | Yes Account and message events with delivery controls |
| Providers and email work | ||
| Provider APIs | Gmail API and Microsoft Graph | Gmail API and Microsoft Graph |
| Generic mailboxes | IMAP and SMTP | IMAP and SMTP |
| Search, read, and attachments | Yes | Yes |
| Draft, send, and organize | Yes | Yes |
| Scheduling and queues | Scheduled send and status tools | Outbox queues, retries, and scheduled send |
| Templates and mail merge | Not built in | Built in |
| Access and licensing | ||
| Agent permissions | Read-only, read-write, full, or custom Plus member and mailbox scope | MCP scopes, permission narrowing, and account binding Tool discovery respects the calling credential |
| Credential encryption | Built-in encryption for provider credentials | Requires EENGINE_SECRET in production Credentials are not encrypted without it |
| Pricing | Free; Pro $15/month; Business $25/member/month Annual billing: Pro $120; Business $240/member | $1,450/year after a 14-day trial Unlimited instances and IMAP accounts; VAT excluded |
EmailEngine ships a native MCP endpoint in beta. It supports reading, organizing, drafting, and sending, and an administrator must enable it. MCP calls use the same authorization as the REST API.
Fluxmail includes a native MCP server with email-specific tools and schemas designed for model use. The same deployment also provides REST routes and a CLI, so agents, applications, and operators can share one email service.
Fluxmail can expose only the tools a client is allowed to use. A research agent can be read-only, an organizer can manage messages without sending, and a drafting agent can work with drafts without permanent deletion. Member access and mailbox allowlists apply separately on every request.
EmailEngine also filters tool discovery by credential, supports permission narrowing and account binding, and separates mail access from instance-management tools. Compare the exact operations each profile allows before connecting an agent.
Fluxmail runs as a local process or Docker service and stores its database in SQLite, so it does not require a separate Redis instance. Its Personal plan remains free for one member and three mailboxes.
EmailEngine requires Redis and provides a fourteen-day trial before its paid production license. Fluxmail is a smaller starting point for personal agents and teams that do not need EmailEngine's additional application infrastructure.
We reviewed the linked product docs on October 8, 2026.
Run Fluxmail on your own infrastructure and use it through MCP, REST API, or CLI.